James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 223.
Katarzyna Mikulska Dabrowska, "'Secret Language' in Oral and Graphic Form: Religious-Magic Discourse in Actec Speeches and Manuscripts," Oral Tradition 25:3 (2010), 325–363, see page 327.